Sentences with phrase «global air temperature at»

Running 60 - month averages of global air temperature at a height of two metres (left - hand axis) and estimated change from the beginning of the industrial era (right - hand axis) according to different datasets: ERA - Interim (Copernicus Climate Change Service, ECMWF); GISTEMP (NASA); HadCRUT4 (Met Office Hadley Centre), NOAAGlobalTemp (NOAA); and JRA - 55 (JMA).

Not exact matches

But if people continue to pump greenhouse gases into the air at current rates, global temperatures could increase by as much as 7.8 °C (about 14 °F) by 2100, the new report points out.

The former is likely to overestimate the true global surface air temperature trend (since the oceans do not warm as fast as the land), while the latter may underestimate the true trend, since the air temperature over the ocean is predicted to rise at a slightly higher rate than the ocean temperature.

Speaking at an annual meeting of the American Association for the Advancement of Science, Barnett said climate models based on air temperatures are weak because most of the evidence for global warming is not even there.

So, if you have two identical glass greenhouses with thermally isolated mercury thermometers at equilibrium in the sunlight [One with Air at Press =P, and the 2nd w / CO2 at Press =P], and you close the blinds — you will see the thermometer in the CO2 greenhouse retain its temperature longer — not because of any «global warming» type effect, but simply because Air conducts heat to the walls of the greenhouse better than Air does.

http://climate.nasa.gov/news/1141/: «Norman Loeb, an atmospheric scientist at NASA's Langley Research Center, recently gave a talk on the «global warming hiatus,» a slowdown in the rise of the global mean surface air temperature.

Thus, small changes of global average air temperature are associated with very large changes in some regions, particularly over land, at mid - to high latitudes, in mountain regions.

And if decreasing carbon emissions turns out not to affect global temperatures, at least it will free us from petroleum dependency and clear up the air.

ie does a slightly lower density of air mean a slightly lower ground level temperature (temperature normally decreases with height at the lower air density), so that in reality adding CO2 and subtracting more O2 actually causes miniscule or trivial global COOLING, and the (unused) ability of the changed atmosphere to absorb radiation energy and transmit it to the rest of the air is overruled or limited by the ideal gas law?

Transient climate sensitivity: The global mean surface - air temperature achieved when atmospheric CO2 concentrations achieve a doubling over pre-industrial CO2 levels increasing at the assumed rate of one percent per year, compounded.

Global average air temperature near the surface is dominated by the ocean (because it covers two thirds of the planet), particularly at low latitudes.

So, if you have two identical glass greenhouses with thermally isolated mercury thermometers at equilibrium in the sunlight [One with Air at Press =P, and the 2nd w / CO2 at Press =P], and you close the blinds — you will see the thermometer in the CO2 greenhouse retain its temperature longer — not because of any «global warming» type effect, but simply because Air conducts heat to the walls of the greenhouse better than CO2 does.

The former is likely to overestimate the true global surface air temperature trend (since the oceans do not warm as fast as the land), while the latter may underestimate the true trend, since the air temperature over the ocean is predicted to rise at a slightly higher rate than the ocean temperature.

Re 9 wili — I know of a paper suggesting, as I recall, that enhanced «backradiation» (downward radiation reaching the surface emitted by the air / clouds) contributed more to Arctic amplification specifically in the cold part of the year (just to be clear, backradiation should generally increase with any warming (aside from greenhouse feedbacks) and more so with a warming due to an increase in the greenhouse effect (including feedbacks like water vapor and, if positive, clouds, though regional changes in water vapor and clouds can go against the global trend); otherwise it was always my understanding that the albedo feedback was key (while sea ice decreases so far have been more a summer phenomenon (when it would be warmer to begin with), the heat capacity of the sea prevents much temperature response, but there is a greater build up of heat from the albedo feedback, and this is released in the cold part of the year when ice forms later or would have formed or would have been thicker; the seasonal effect of reduced winter snow cover decreasing at those latitudes which still recieve sunlight in the winter would not be so delayed).

One I have recently submitted feedback on is «Global surface air temperatures rose three - quarters of a degree Celsius (almost one and a half degrees Fahrenheit) in the last century, but at twice that amount in the past 50 years.»

As such; there is always an extra cost of containing such gases as a part of the requirements of environmental policy makers to help control the rise in global temperature, so that the environment is kept at a reasonable composition of the fresh air and dangerous natural gases.

Sealing time of air bubbles at best about 70 years and mixing with ambient air through diffusion all that time, chemical changes thereafter, different diffusion rates for different gases thereafter... ice cores are a target - rich environment for casting of doubt about how well they perform as global temperature proxies.

Water takes longer to heat up and cool down than does the air or land, so ocean warming is considered to be a better indicator of global warming than measurements of global atmospheric temperatures at the Earth's surface.

Specifically, the cloud cover is multiplied by the factor 1 + c T, where T, computed every time step, is the deviation of the global mean surface air temperature from the long - term mean in the model control run at the same point in the seasonal cycle and c is an empirical constant.

The resulting enhanced loss of summer and winter sea ice resulted in feedbacks, associated with Arctic Amplification, which has raised Arctic air temperatures at a rate twice the global average.

Stepping back from there, Hansen looks at 1940 and above: «The approximate stand - still of global temperature during 1940 - 1975 is generally attributed to an approximate balance of aerosol cooling and greenhouse gas warming during a period of rapid growth of fossil fuel use with little control on particulate air pollution, but quantitative interpretation has been impossible» That's the excuse and it is laughable.

Internal variability can only account for ~ 0.3 °C change in average global surface air temperature at most over periods of several decades, and scientific studies have consistently shown that it can not account for more than a small fraction of the global warming over the past century.

If we make it to next week, we'll look at another double - sided threat: air pollution is killing millions, but if we clean it up, the global mean temperature may go up as much as 1 degree C. We'll hear what the scientists say about new research.

The global warming signal itself is a multidecadal feature of the climate, but just like the seasonal example above, it has been possible at times to take one period of one temperature record - surface air temperatures in most cases - and do a «January - February» job with it, thereby making the claim that temperatures are flatlining or even cooling.

A new study on ice loss in Antarctica by the British Antarctic Survey confirms what we already know about the effects of global warming but it differentiates between the effects of ocean currents, their cause and the air temperature effects at the ice surface.

However, despite this, the team reckon to have perhaps isolated a «global warming» signal in the accelerated run off of the Greenland Ice Mass — but only just, because the runoff at the edges is balanced by increasing central mass — again, they focus upon recent trends — a net loss of about 22 cubic kilometres in total ice mass per year which they regard as statistically not significant — to find the «signal», and a contradiction to their ealier context of air temperature cycles.

Confirming what we already know about the effects of global warming, it also differentiates between the effects of currents, their cause and the air temperature effects at the ice surface.

The global warming rate at the stations used in the analysis, using all days» data, is the same as that reported using all available stations by Jones, P.D. and A. Moberg, «Hemispheric and large - scale surface air temperature variations: An extensive revision and an update to 2001», Journal of Climate 16: 206 - 223 (2003).

To point out just a couple of things: — oceans warming slower (or cooling slower) than lands on long - time trends is absolutely normal, because water is more difficult both to warm or to cool (I mean, we require both a bigger heat flow and more time); at the contrary, I see as a non-sense theory (made by some serrist, but don't know who) that oceans are storing up heat, and that suddenly they will release such heat as a positive feedback: or the water warms than no heat can be considered ad «stored» (we have no phase change inside oceans, so no latent heat) or oceans begin to release heat but in the same time they have to cool (because they are losing heat); so, I don't feel strange that in last years land temperatures for some series (NCDC and GISS) can be heating up while oceans are slightly cooling, but I feel strange that they are heating up so much to reverse global trend from slightly negative / stable to slightly positive; but, in the end, all this is not an evidence that lands» warming is led by UHI (but, this effect, I would not exclude it from having a small part in temperature trends for some regional area, but just small); both because, as writtend, it is normal to have waters warming slower than lands, and because lands» temperatures are often measured in a not so precise way (despite they continue to give us a global uncertainity in TT values which is barely the instrumental's one)-- but, to point out, HadCRU and MSU of last years (I mean always 2002 - 2006) follow much better waters» temperatures trend; — metropolis and larger cities temperature trends actually show an increase in UHI effect, but I think the sites are few, and the covered area is very small worldwide, so the global effect is very poor (but it still can be sensible for regional effects); but I would not run out a small warming trend for airport measurements due mainly to three things: increasing jet planes traffic, enlarging airports (then more buildings and more asphalt — if you follow motor sports, or simply live in a town / city, you will know how easy they get very warmer than air during day, and how much it can slow night - time cooling) and overall having airports nearer to cities (if not becoming an area inside the city after some decade of hurban growth, e.g. Milan - Linate); — I found no point about UHI in towns and villages; you will tell me they are not large cities; but, in comparison with 20-40-60 years ago when they were «countryside», many small towns and villages have become part of larger hurban areas (at least in Europe and Asia) so examining just larger cities would not be enough in my opinion to get a full view of UHI effect (still remembering that it has a small global effect: we can say many matters are due to UHI instead of GW, maybe even that a small part of measured GW is due to UHI, and that GW measurements are not so precise to make us able to make good analisyses and predictions, but not that GW is due to UHI).

However, despite all that, the weather systems combined with the hydrological cycle and the global air circulation guided by the sea surface temperatures do provide reasonable overall stability for eons at a time by neutralising many potentially disruptive natural and biologically induced variables affecting air temperature.

Following a warming trend early in the 20th century and mid-century cooling, surface air temperatures in the Arctic have shown a strong increase over the last few decades, warming at about twice the global average.

The only warming that can be ferreted out of the temperature records is in the coldest and most inhospitable regions on Earth, such as in the dry air of the Arctic or Siberia where going from a -50 °C to a -40 °C at one small spot on the globe is extrapolated across tens of thousands of miles and then branded as global warming.

At the end of the day, the discussion about a single calendar year obscures the more important long - term trend of warming air temperatures, warming and acidifying oceans along with melting ice sheets, all of which are hallmarks of manmade global warming.

As a massive blanket of arctic air brings twenty - year record cold temperatures to the United States, it's not surprising to see the Church of Global Warming in full - on shrieking panic mode, screaming at the top of their lungs that a blast of cold weather doesn't disprove their theories.

By John Hayward — As a massive blanket of arctic air brings twenty - year record cold temperatures to the United States, it's not surprising to see the Church of Global Warming in full - on shrieking panic mode, screaming at the top of their lungs that a blast of cold weather doesn't disprove their theories.

What the report says about climate change and the Arctic: Over the past 50 years, near - surface air temperatures across Alaska and the Arctic have increased at a rate more than twice as fast as the global average.

The global annual mean surface air temperature change... centred at the time of CO2 doubling in a 1 % per year compound CO2 increase scenario.

It is not «conduction» but exchange of radiation; if you keep your hands parallel at a distance of some cm the right hand does not (radiatively) «warm» the left hand or vice versa albeit at 33 °C skin temperature they exchange some hundreds of W / m ² (about 500 W / m ²) The solar radiation reaching the surface (for 71 % of the surface, the oceans) is lost by evaporation (or evapotranspiration of the vegetation), plus some convection (20 W / ²) and some radiation reaching the cosmos directly through the window 8µm to 12 µm (about 20 W / m ² «global» average); only the radiative heat flow surface to air (absorbed by the air) is negligible (plus or minus); the non radiative (latent heat, sensible heat) are transferred for surface to air and compensate for a part of the heat lost to the cosmos by the upper layer of the water vapour displayed on figure 6 - C.

On a slightly tangential topic, why do we use a «global temperature» parameter that is a compound of sea surface temperature (or about 1 metre below the surface or whatever) and air temperature (at about 1 to 2 metres above the surface)?

Subsurface ocean warming explains why global average air temperatures have flatlined since 1999, despite greenhouse gases trapping more solar heat at the Earth's surface.

Though global warming is a factor in Rio's rising air temperatures, urban expansion is at least partly responsible.

When you hear the term «global warming,» do you think of the warming of air temperatures at the Earth's surface, or the warming of the planet as a whole?

The thawing of permafrost in the region has been linked to global warming.5 Annual average air temperatures rose 1.1 ° F (0.6 ° C) from 1960 to 2005,6,11,12 while permafrost at a depth of 33 feet (10 meters) warmed an average of 0.5 ° -1.3 ° F (0.3 ° -0.7 ° C).6, 12

They identified at least three different definitions of any so - called hiatus, different judgments of the extent of the period under discussion and different starting points, and of course the problem of different datasets of global air surface temperatures.

Global temperatures usually are described in terms of the surface air temperature anomaly, the deviation of the temperature at each site from a mean of many years that is averaged over the whole world, both land and oceans.

Changing global temperatures induce air circulation changes as the air seeks to restore the sea surface / surface air temperature equilibrium and at the same time resolve ocean induced variations in the sun to sea / air to space equilibrium.

Greenland surface air temperature trends, including at the Summit site, have not shown persistent warming since 1930 in contrast to global average surface temperature (23).

For this to be true you would have to prove that minor long - term global air temperature variations drive ocean oscillations and that these ocean oscillations — at some later point — influence global long - term air temperature trends....

RealClimate is wonderful, and an excellent source of reliable information.As I've said before, methane is an extremely dangerous component to global warming.Comment # 20 is correct.There is a sharp melting point to frozen methane.A huge increase in the release of methane could happen within the next 50 years.At what point in the Earth's temperature rise and the rise of co2 would a huge methane melt occur?No one has answered that definitive issue.If I ask you all at what point would huge amounts of extra methane start melting, i.e at what temperature rise of the ocean near the Artic methane ice deposits would the methane melt, or at what point in the rise of co2 concentrations in the atmosphere would the methane melt, I believe that no one could currently tell me the actual answer as to where the sharp melting point exists.Of course, once that tipping point has been reached, and billions of tons of methane outgass from what had been locked stores of methane, locked away for an eternity, it is exactly the same as the burning of stored fossil fuels which have been stored for an eternity as well.And even though methane does not have as long a life as co2, while it is around in the air it can cause other tipping points, i.e. permafrost melting, to arrive much sooner.I will reiterate what I've said before on this and other sites.Methane is a hugely underreported, underestimated risk.How about RealClimate attempts to model exactly what would happen to other tipping points, such as the melting permafrost, if indeed a huge increase in the melting of the methal hydrate ice WERE to occur within the next 50 years.My amateur guess is that the huge, albeit temporary, increase in methane over even three or four decades might push other relevent tipping points to arrive much, much, sooner than they normally would, thereby vastly incresing negative feedback mechanisms.We KNOW that quick, huge, changes occured in the Earth's climate in the past.See other relevent posts in the past from Realclimate.Climate often does not change slowly, but undergoes huge, quick, changes periodically, due to negative feedbacks accumulating, and tipping the climate to a quick change.Why should the danger from huge potential methane releases be vievwed with any less trepidation?

One of the observational records employed in the GISS analysis is the Global Historical Climatology Network (GHCN) data set for surface air temperature at meteorological stations, which is maintained by the National Oceanic and Atmospheric Administration (NOAA) National Climatic Data Center (NCDC).